This document defines key ecological terms and describes different habitats. It explains that a community is made up of living organisms in a habitat. An ecosystem is a community interacting with its physical surroundings. A habitat provides conditions for an organism's development and is defined by physical and biotic factors. Examples of habitats described include deserts, rainforests, tundra, prairies, savannahs, forests, and marine and zoo environments. Niche refers to an organism's role and interactions within its habitat and ecosystem.